Vibrio parahaemolyticus is a Gram-negative, halophilic, human pathogenic bacterium ubiquitous in the marine environment. Like many Vibrio species, V. parahaemolyticus commonly associates with shellfish, particularly oysters. Ingestion of a raw or under cooked oysters contaminated with V. parahaemolyticus can cause gastroenteritis, which is typically self-limiting and rarely causes death. Globally,...
The pathogen Vibrio cholerae uses cations as a primary currency of virulence
and environmental persistence, using gradients of those cations to move, acquire
nutrients, and control virulence gene expression. An understanding of the overlapping
roles of bioenergetics and chemotaxis in the virulence and environmental survival of
V. cholerae issues from...
The purpose of this project is to study which methyl-accepting chemotaxis proteins (MCPs) are related to chemotaxis of Vibrio cholerae. 44 MCP mutant strains were tested in seven different chemoattractants and the resulting swarm circle size was compared to that of C6706 lac-Z wildtype. Several genes were identified that resulted...
We found that a strains of Yersinia pestis (KIM5) which lacked the nhaA gene was fully attenuated in a plague model. This gene produces a protein of the sodium-proton antiporter family which expel sodium ions from the bacterial cytoplasm in exchange for hydrogen ions, or protons, from the surrounding environment....
Vibrio cholerae is the causative agent of cholera, a serious diarrheal disease in developing countries. V. cholerae has a unique redox driven respiration-linked sodium pump, Na⁺ translocating NADH:quinone oxidoreductase (NQR). Several reports previously showed that NQR plays an important role in virulence, metabolism, and sodium homeostasis of V. cholerae. This...
Haemonchus sp. is known to be present in geographical regions of Oregon that are more arid and warm, which has been the preferred climate of this parasite. However, it was not detected in Western Oregon bovine until recently. Haemonchus sp. was first detected in Western Oregon bovine from a fecal...
The ability to move towards favorable environmental conditions, called chemotaxis, is common among motile bacteria. In particular aerotaxis has been extensively studied in Escherichia coli. Three putative aer gene homologs were identified in the V. cholerae genome designated VCAer-1 (VC0512) VCAer-2 (VCA0658), and VCAer-3 (VCA0988). Deletion analyses indicated that only...
Pseudomonas aeruginosa is a bacterial pathogen that can cause grave and sometimes chronic infections in patients with weakened immune systems and cystic fibrosis. It is suspected that specialized sodium pumps in the cellular membrane are crucial for the organism’s survival and growth, since many cellular processes rely on the maintenance...
Vibrio cholerae (Vc), the etiological agent of cholera, has developed many mechanisms to combat the great fluctuations in pH, ion content and osmotic conditions of the vastly differing environments it encounters through its infections of the human host. A series of cation antiporters are found in the Vc membrane to...
Vibrio parahaemolyticus, a naturally occurring halophilic pathogen, is seasonally abundant in marine and estuarine environments. It is also the leading cause of gastroenteritis in humans world-wide. Numerous outbreak incidences associated with the pathogenic Vibrio parahaemolyticus contaminations in oyster products have raised public-health concerns as well as economic challenges to the...